建立了使用聚合膜修饰电极测定维生素B6的新方法.在pH6.80的磷酸盐缓冲溶液(PBS)中,用循环伏安法在玻碳电极上制备聚L-谷氨酸修饰膜,并且研究维生素B6在聚L-谷氨酸膜修饰电极上的电化学行为及测定方法,即在外加电压为0条件下流动注射双安培法测定维生素B6的电化学分析方法.在0.1 mol/L PBS (pH 6.80)载液中,维生素B6在聚L-谷氨酸修饰电极上产生一不可逆氧化峰,在选定的最佳试验条件下,流动注射双安培法测定维生素B6氧化峰峰电流与其浓度在4.0×10-6 ～2.0 × 10-3 mol/L范围内呈线性关系(r =0.993 5,n=10),检出限为9.0×10-7 mol/L,连续测定4.00×10-4 mol/L维生素B6标准溶液20次,电流值RSD为1.05％,进样频率为120 样/h.该方法具有较高的选择性和灵敏度,样品处理方法简单、快速.使用修饰电极建立流动注射双安培法所得线性范围宽,检出限低,可成功应用于西药维生素B6片剂中含量测定,结果令人满意.%A new method for the determination of vitamine B6 was established by using polymer modified electrode in this paper. In pH 6. 80 phosphate buffer solution, the poly (L-glutamic acid) modified electrode was prepared by using cyclic voltammetric method on the bare glassy carbon electrode. The voltammetric behavior of vitamine B6 at the poly( L-glutamic acid) modified electrode has been investigated, and flow injection irreversible biamperometry analysis method were studied under the applied potential difference of 0 V to determinate vatamine B6. In 0.1 mol/L (pH 6. 80) phosphate buffer solution, a sensitive and irreversible oxidation peak was obtained at the poly( L-glutamic acid)modified electrode. Under the optimum conditions, vitamine B6 can be determined over the range 4. 0 × 10 mol/L-2. 0 × 10 mol/L with the sampling frequency of 120 samples per hour. The detection limit for vitamine B6 is 9.0 × 10-7 mol/L and the RSD for 20 replicate determinations of 4.0 × 10-4 mol/L vitamine B6 is 1.05%. The method is simple, with high selective rapid and sensitive. The linear range is large, and the detection limit is slow. The method was applied to the determination of vitamine B6 in the drug with satisfactory results.
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